Objective: The first major phylogenetic split in vascular land plants was between the lycophytes (or lycopsids) and the lineage that gave rise to all other living (and many extinct) vascular plants. The goal of this lab is to become familiar with the lycopsid clade. We will start by reviewing modern lycopsids to learn more about their morphology, anatomy, biology and evolutionary relationships. This will give a grounding to interpret the structures of ancient members of the lineage. The earliest lycopsid is the Silurian Baragwanathia from Australia. The Silurian age of Baragwanathia suggests that this plant, with true leaves, existed at a time when Cooksonia was the only other evidence of vascular plants on land. We will then revisit the Rhynie Chert to look at another early lycopsid that lacks true leaves, and then follow the evolution of arborescence in this group. An important theme through the next few labs will be convergent evolution between plants of the lycopsid clade and the "everything else" clade or "euphyllophytes". Think about some of these convergences as you study the lycopsids and consider the environmental conditions that might have permitted their survival.